Surgical drape

ABSTRACT

An improved disposable surgical drape of the type that includes a primary operative area and the fenestrations therein, comprising a fibrous base sheet, a fluid impervious plastic film covering said primary operative area, and an open celled fluid absorbent foam material overlying the plastic film, the improvement comprising means for communicating an external source of reduced air pressure, the reduced air pressure being effective to provide a suction force for removing fluid absorbed in the foam material, the communicating means being located intermediate the film and foam material at least near the fenestration.

United States Patent [191 Schrading [451 Oct. 9, 1973 Primary Examiner-Charles F. Rosenbaum Attorney-C. Frederick Leydig et a1.

[5 7 ABSTRACT An improved disposable surgical drape of the type that includes a primary operative area and the fenestrations therein, comprising a fibrous base sheet, a fluid impervious plastic film covering said primary operative area, and an open celled fluid absorbent foam material overlying the plastic film, the improvement comprising means for communicating an external source of reduced air pressure, the-reduced air pressure being effective to provide a suction force for removing fluid absorbed in the foam material, the communicating means being located intermediate the film and foam material at least near the fenestration.

9 Claims, 4 Drawing Figures SURGICAL DRAPE CROSS REFERENCE TO RELATED APPLICATIONS Donnelly, Ser. No. 17,431 filed Mar. 9, I970. Schrading and Winters, Ser. No. 58,336 filed July 27, 1970. Winters, Ser. No. 223,990 filed Feb. 7, 1972.

DESCRIPTION OF THE INVENTION The present invention relates generally to disposable surgical drapes and, more particularly, to surgical drapes having absorbent foam material covering the primary operative area.

In recent years, there have been many new commercial developments in disposable articles for use in hospitals, clinics and the like, particularly with respect to surgical drapes that are intended for a single use. A significant commercial market has been created for such disposable articles because they are less expensive to initially produce and need not be laundered or resterilized since they are intended for only a single use. Since labor costs associated with laundering and sterilizin g have increased significantly and are generally predicted to rise in the future, it is expected that such disposable articles will enjoy an increasing market. In addition to the above advantages, specialized disposable articles such as surgical drape sheets have other advantages owing to the fact that they can be inexpensively produced in that specific structural features can be incorporated into their construction for particular speciflc operations or the like. These features may result in a more effective product that is tailored toward a particular operation and may include constructional features that would be unsuitable in a conventional drape that is intended for use in many differing types of operations.

Among the more significant recent developments in disposable surgical drapes are those drapes disclosed in the Donnelly application, Ser. No. 17,431 filed Mar. 9, 1970, as well as the Schrading and Winters application, Ser. No. 58,336 filed July 27, 1970, all of which are assigned to the assignee of the present invention. Features common to the surgical drapes disclosed in these applications involve a fibrous base sheet and a filmfoam laminate including fluid absorbent plastic foam material in the primary operative area of the surgical drape. As disclosed in these applications, the presence of the absorbent foam material on the exposed surface of the primary operative area near the fenestration (if a fenestration is present) has been found to be a very desirable feature in that it has a frictional coefficient that prevents dislodgement of surgical instruments, supplies and the like when placed on the surface of the sheet during an operation. The foam material is also stable at conditions encountered during sterilization treatments either by steam or ethylene oxide or the like, and the open celled foam material is also fluid absoibent to minimize fluid run off that is invariably encountered during most surgical operations. It should be understood, however, that the ultimate capacity of the absorbent foam material to retain fluids is, of course, limited by the thicknesses of the foam material applied to the surgical drape sheet and, in this connection, foam thicknesses within the range of about 25 to I mils are within the general range of use. Thus, it is seen that while the absorbency of the foam material is a very desirable attribute that minimizes the possibility of fluid run off, particularly in the primary operative area, the ultimate fluid capacity of the foam material is necessarily limited.

Accordingly, it is a primary object of the present invention to provide an improved disposable surgical drape having an open celled foam material on the outer surface wherein fluids absorbed by the foam material are removed to provide relatively unlimited fluid capacity in the primary operative area of the drape.

Yet another object of the present invention is to provide a disposable surgical drape of the type that includes a fenestration in the primary operative areaand utilizes an absorbent open celled foam material on the outer surface in the primary operative area, wherein the drape includes means for applying a reduced air pressure beneath the foam material for removing fluids that are present therein.

A still further object of the invention lies in the provision of an improved surgical drape having the aforementioned desirable characteristics and yet which is adapted to be easily connected to sources of reduced air pressure that are present in most operating rooms. A related object is to provide such a surgical drape which is operational and compatable with levels of reduced air pressure generated by vacuum sources found in most operating rooms.

Still another object of the invention is to provide an improved surgical drape having the above desirable characteristics wherein the means for removing the fluid is internally located in the primary operative area, and is flexible to retain the desired draping characteris: tics of the surgical drape.

A still further'object of the present invention lies in the provision of an improved surgical drape having all of the aforementioned desirable characteristics and yet which can be produced at a sufficiently low cost to permit disposal of the drape after a single use.

Other objects and advantages of the present invention will become readily apparent from the ensuing detailed description and accompanying drawings, in which:

FIG. 1 is a plan view of a surgical drape embodying the present invention;

FIG. 2 is a section taken generally along the line 2-2 in FIG. 1;

FIG. 3 is a plan view of another surgical drape, which also embodies the present invention; and

FIG. 4 is a section taken generally along the line 4-4 in FIG. 3. I

While the invention is susceptible of various modifications and alternative forms, certain specific embodiments thereof have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that it is not intended to limit the-invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as expressed in the appended claims. In this connection, a laparotomy drape has been shown in the drawings, and it should be understood that other types of surgical drapes may be used and that the invention is not limited to the particular type of surgical drape illustrated. Similarly, the specific embodiment of the base sheet is described as comprising outer layers of cellulosic wadding and inner layers of highly drafted fibers. It should be understood that the construction of the base sheet should not be limited to the specific base sheet disclosed.

Turning now to the drawings, there are shown in FIGS. 1 and 3 surgical drapes, indicated generally at 10, 12 and 14, respectively, each of which have a fenestration 16 and a primary operative area, which is the fenestration area of the illustrated surgical drape. The surgical drapes disclosed in the drawings are laparotomy sheets which are elongated, generally rectangular sheets used to cover the patient during thoracic or abdominal surgery, and and typically about 6 to 8 feet in length and about 3 to 6 feet in width. Each of the drapes has a fibrous base sheet 20 which preferably comprises outer layers of cellulosic wadding and inner layers of highly drafted fibers disposed angularly relative to each other. A spaced pattern of adhesive is disposed between each fiber layer and its adjacent wadding layer with the fibers in each layer partially embedded in and held by the adhesive in the adjacent adhesive layer where it extends between the fibers of its adjacent fiber layer and with a portion of the adhesive in both adhesive layers joined where the adhesive patterns are superimposed. This material is described in more detail in copending Sokolowski et al. U.S. Pat. No. 3,484,330, assigned to the assignee of the present invention.

Turning now to the specific embodiment of the present invention illustrated in FIGS. 1 and 2, the drape 10 has a fluid impervious plastic layer or film 22 bonded to the fibrous base sheet by any suitable means, but preferably by means of an adhesive. The film 22 provides a fluid impervious barrier in the primary operative area so that any fluids contacting this area cannot strike through the drape. This prevents the transfer of bacteria and thereby helps insure that sterile conditions will be maintained in the primary operative area. It should be understood that the film must be capable of remaining stable under the conditions encountered in the particular treatment to which the drape sheet is subjected to render it sterile, i.e., temperatures of about 270F for steam sterilization or about 160F for sterilization by means of ethylene oxide or the like. Examples of suitable films are polyethylene, e.g., 2 mil polyethylene film manufactured by Clopay Corp., Cincinnati, Ohio; polypropylene, e.g., "Extrel ll available from Extrudo Film Corp., New York, N.Y.; polyethylene methylacrylate co-polymer film manufactured by Edison Plastic Company; and vinylchloride films. The films should be substantially free of pin holes to provide the desired sterility barrier, and thus must generally be at least 0.15 mil thick.

Overlying the fluid impervious film 22 is an open celled foam material 24 which may be bonded to the film 22 by any suitable means, but preferably by means of an adhesive. The foam material 24 is preferably quite absorbent due to either the degree of openers in its open celled structure or by virtue of its hydrophilicity to minimize the run off of fluids that are encountered in the fenestration area and absorb them. The hydrophilicity may be an inherent property of certain foam materials or may be imparted to a normally hydrophobic material by a treatment such as disclosed in the Winters application, Ser. No. 223,990, filed Feb. 7, 1972, and assigned to the assignee of the present invention.

The layer of fluid impervious film 22, however, prevents the absorbed fluids from striking through the drape. As previously stated, the relatively high coefficient of friction of the foam material provides a substantially non-slip surface which prevents accidental dislodgement of surgical instruments and the like when they are placed on the surface of the foam material during a surgical operation. Additionally, the foam material 24 preferably has a low glare which is achieved in part by its open cellular structure and which may be enhanced by tinting or coloring the foam during its manufacture or subsequently thereof. The foam thickness should preferably be in the range of about 25 mils to about mils. Examples of suitable foams are 40 mil polyester polyurethane foam having a density of 1.7 lbs/ft, available from Reeves, New York, N.Y., or Tenneco Chemicals Inc., New York, N.Y., as well as other polyether polyurethane foams.

Suitable adhesives for use in bonding the foam material to the film and for bonding the film to the base sheet are preferably water resistant adhesives that are solvent based. While the bonding of the film to the base sheet may be performed using similar adhesive and loading the adhesive is preferably continuous around the fenestration and around the outer periphery of the film.

With respect to the locations where adhesive is placed to bond the foam material to the film, it is also preferred that the adhesive be continuous around the periphery of the fenestration and around the outer peripheral area of the foam material. However, the foam material should not be bonded to the film in the fenestration area outwardly of the fenestration periphery for reasons that will hereinafter be disclosed.

In accordance with an aspect of the present invention, a flexible conduit or tube 30 is positioned between the foam and film layers 24, 22 with one end portion generally surrounding the fenestration 16 as illustrated in FIG. 1. The other end portion extends from the fenestration area outwardly of the primary operative area and has a free end portion 32 that should be of sufficient length to be connected to the source of vacuum or reduced air pressure that is available in most operating rooms. The interior end portion preferably has its end 34 sealed. The flexible tubing 30 should be spaced away from the fenestration 16 a moderate distance, for example 2 to 4 inches, so that it does not appreciably increase the thickness of the drape immediately adjacent the fenestration so as to possibly interfere with the operation. Spaced along the tubing at the end portion surrounding the fenestration are a number of apertures 36 which communicate the reduced air pressure to the underside of the foam. The apertures may be of increasing diameter as they approach the end 34 to communicate a more uniform reduced air pressure around the entire fenestration area. In this connection, it should be understood that the pressure will be correspondingly lower within the tubing for those apertures that are nearer to the vacuum or reduced air pressure source. The tubing should be sufficiently small that undesirable bulges in the drape are not readily apparent and should also be sufficiently flexible yet noncollapsible at the vacuum or suction levels employed so that the desirable draping characteristics are not significantly impaired.

Be selectively providing the number and size of the apertures so that the total area of the apertures approximates the area of conventionally used bowie tubes, the suction force created by the apertured portion of the tubing or conduit 30 willbe compatable with reduced air pressure or vacuum sources that are available in operating rooms. In this connection, the conventional bowie tubes have an inside diameter of approximately /4 square inch and the vacuum sources present in most operating rooms are within the range of about to inches of mercury. Also, many sources of vacuum are of the pulsating type that are desirable in that the probability of blocking is reduced. The present invention is compatable with such pulsating sources as well as with a source having a constant level of vacuum.

With respect to the bonding of the foam material to the film, it is preferred that the foam material not be bonded to the film in the immediate area of the portion of the tubing that contains the apertures 36, i.e., the portion of the tubing surrounding the fenestration, so that the vacuum or reduced air pressure will create a suction force over a larger area. The tubing is positioned around the fenestration since the fluids encountered during an operation originate at the fenestration area and, accordingly, the placement of the apertured portion of the tubing is in a location adapted to intercept the absorbed fluid and remove it through the external portion of the tubing.

Turning now to the embodiments of the surgical drape of the present invention exemplified in FIGS. 3 and 4, a fluid impervious plastic film is bonded to the fibrous base sheet 20 by any suitable means, and preferably by means of an adhesive, such as that disclosed with respect to the previously described surgical drape 10. While the bonding of the film 40 to the base sheet 20 may be performed using similar adhesive, loading and pressure, the adhesive is preferably applied in a spaced pattern to maintain optimum flexibility of the resulting drape. The film 40 may cover substantially the entire primary operative area as shown in FIG. 3 or may be substantially smaller to cover only the area near the fenestration. I

In keeping with the present invention, the drape sheet has, in the primary operative area, a layer of open celled, absorbent foam material 42 on its outer surface with a second layer of plastic film 44 bonded thereto. The layers of plastic film 40 and 44 are preferably of the type described with respect to the film-22 hereinbefore described.

In accordance with an aspect of the present invention, a layer of flexible, non-collapsable material 46 is positioned intermediate the layers 40 and 44 of the plastic film. The material 46 should be adapted to communicate fluid therethrough and yet should be sufficiently non-collapsable to the extent that it can withstand the levels of reduced air pressure being supplied by vacuum sources present in operating rooms. In this connection, the material may be an open celled foam material that has large pores such that liquid may easily communicate through it. The area of the intermediate layer 46 should preferably be slightly smaller than the area of the film 40, i.e., it should be inwardlyspaced from the outer peripheral edge of the film 40 as well as being spaced away from the fenestration 16 so that the films 40 and 44 contact one another around these peripheries. In the event a heat sealable film, such as polyethylene is used, the film 40 and 44 may be heat sealed to one another around the lines 48 and 50 to form a fluid reservoir.

To enable the fluid absorbed by the foam material to pass into the intermediate layer 46, the film 44 laminated to the foam 42 is apertured in the area that is coextensive with the intermediate layer 46. While the apertures may be made by many differing means, it is preferred that the foam and film layer 42, 44 be either pin embossed or needled after they have been bonded together, with the needling or pinembossing being effective to introduce a plurality of relatively small holes or breaks in the film 44 that enable the absorbed fluid to pass from the foam through the film 44 and into the intermediate layer 46.

In keeping with the present invention, the drape 12 has a flexible tube or conduit 54, which is adapted to have its external end connected to the source of reduced air pressure or vacuum in the manner described with respect to the tubing 30 associated with the drape 10. Referring to FIG. 3, it is seen that the internal portion of the tubing 54 surrounds the fenestration in a generally meandering path so that it covers a substantially larger surface area which is shown to be a major portion of the primary operative area. The internal portion of the flexible conduit 54, contains a number of apertures 36, the size and spacing of which are also simi-.

lar to that previously described with respect to the drape 10.

Thus, it should be understood that a new and useful surgical drape having relatively unlimited absorbent capacity by virtue of the means for removing the absorbed fluid has been shown and described. The construction of the surgical drape of the present invention is such that the desirable attributes of the drapes described in the related applications are maintained, and yet has significant improved desirable attributes as have been herein described.

I claim as my invention:

1. An improved disposable surgical drape having a primary operative area and a fenestration in said primary operative area, said drape comprising the combination of a flexible fibrous base sheet, a fluid impervious plastic film laminated to one surface of the base sheet and covering said primary operative area, and a sheet of fluid absorbent open celled plastic foam material covering said fluid impervious film, the improvement comprising means for communicating an external source of reduced air pressure to the underside of said fluid absorbent foam material adjacent said fenestration, said foam material being bonded to said fluid impervious film at least intermittently around the periphery of said fenestration, said means being effective to communicate said reduced air pressure to provide a suction force for removing fluids from said foam material.

2. An improved disposable drape as defined in claim 1 wherein said means comprises a flexible conduit located intermediate said foam material and fluid impervious film, said conduit extending externally of said primary operative area, said conduit extending around said fenestration in spaced relation relative to the periphery of said fenestration and including a number of apertures where it surrounds the fenestration so as to communicate said reduced air pressure to the underside of the foam material near said fenestration.

3. An improved disposable surgical drape as defined in claim 2, wherein said conduit is flexible plastic tub- 4. An improved disposable surgical drape of the type having a primary operative area and a fenestration in said operative area, comprising, in combination:

a fibrous base sheet;

a first fluid impervious plastic film bonded to said fibrous base sheet adjacent said fenestration and extending outwardly therefrom;

a flexible intermediate layer overlying said first plastic film, said layer being adapted to communicate fluid therethrough;

a second plastic film overlying said intermediate layer, said second plastic film having a plurality of apertures therein adapted to communicate fluid to said intermediate layer;

a fluid absorbent, open celled, flexible plastic foam material bonded to said second film; and

means for communicating an external source of reduced air pressure to said flexible intermediate layer, said reduced air pressure being effective to provide a suction force for removing fluids from said foam material through said apertures in said second plastic film, said communicating means including an external flexible conduit for communieating said reduced air pressure to said intermediate layer and for removing said fluids from said surgical drape.

5. An improved disposable drape as defined in claim 4 wherein said communicating means includes passages in said intermediate layer adapted to selectively communicate said reduced air pressure generally equally in the area surrounding said fenestration to said flexible conduit.

6. An improved disposable surgical drape as defined in claim 4 wherein said communicating means includes said flexible conduit extending externally within said intermediate layer, said conduit extending generally throughout the primary operative area and surrounding said fenestration, said conduit having a plurality of apertures in said primary operative area, said apertures varying in size to provide a generally constant reduced air pressure throughout the length of said conduit in said primary operative area so that said suction force is generally constant throughout the primary operative area.

7. An improved disposable surgical drape as defined in claim 4 wherein said first fluid impervious plastic film covers a relatively small area near said fenestration, said second film encompassing a major portion of said primary operative area, said flexible intermediate area being generally smaller than said first plastic film such that said first and second films contact one another around the periphery of said fenestration and the periphery of said first plastic film.

8. An improved disposable surgical drape as defined in claim 7 wherein said first and second films are essentially continuously bonded together around said fenestration and around the periphery of said first plastic film to thereby form a reservoir for retaining fluid entering therein through said apertures in said second plastic film until said fluid is expelled through said communicating means.

9. An improved disposable surgical drape as defined in claim 8 wherein said first and second films are heat sealed to form said bond. 

1. An improved disposable surgical drape having a primary operative area and a fenestration in said primary operative area, said drape comprising the combination of a flexible fibrous base sheet, a fluid impervious plastic film laminated to one surface of the base sheet and covering said primary operative area, and a sheet of fluid absorbent open celled plastic foam material covering said fluid impervious film, the improvement comprising means for communicating an external source of reduced air pressure to the underside of said fluid absorbent foam material adjacent said fenestration, said foam material being bonded to said fluid impervious film at least intermittently around the periphery of said fenestration, said means being effective to communicate said reduced air pressure to provide a suction force for removing fluids from said foam material.
 2. An improved disposable drape as defined in claim 1 wherein said means comprises a flexible conduit located intermediate said foam material and fluid impervious film, said conduit extending externally of said primary operative area, said conduit extending around said fenestration in spaced relation relative to the periphery of said fenestration and including a number of apertures where it surrounds the fenestration so as to communicate said reduced air pressure to the underside of the foam material near said fenestration.
 3. An improved disposable surgical drape as defined in claim 2, wherein said conduit is flexible plastic tubing.
 4. An improved disposable surgical drape of the type having a primary operative area and a fenestration in said operative area, comprising, in combination: a fibrous base sheet; a first fluid impervious plastic film bonded to said fibrous base sheet adjacent said fenestration and extending outwardly therefrom; a flexible intermediate layer overlying said first plastic film, said layer being adapted to communicate fluid therethrough; a second plastic film overlying said intermediate layer, said second plastic film having a plurality of apertures therein adapted to communicate fluid to said intermediate layer; a fluid absorbent, open celled, flexible plastic foam material bonded to said second film; and means for communicating an external source of reduced air pressure to said flexible intermediate layer, said reduced air pressure being effective to provide a suction force for removing fluids from said foam material through said apertures in said second plastic film, said communicating means including an external flexible conduit for communicating said reduced air pressure to said intermediate layer and for removing said fluids from said surgical drape.
 5. An improved disposable drape as defined in claim 4 wherein said communicating means includes passages in said intermediate layer adapted to selectively communicate said reduced air pressure generally equally in the area surrounding said fenestration to said flexible conduit.
 6. An improved disposable surgical drape as defined in claim 4 wherein said communicating means includes said flexible conduit extending externally within said intermediate layer, said conduit extending generally throughout the primary operative area and surrounding said fenestration, said conduit having a plurality of apertures in said primary operative area, said apertures varying in size to provide a generally constant reduced air pressure throughout the length of said conduit in said primary operative area so that said suction force is generally constant throughout the primary operative area.
 7. An improved disposable surgical drape as defined in claim 4 wherein said first fluid impervious plastic film covers a relatively small area near said fenestration, said secoNd film encompassing a major portion of said primary operative area, said flexible intermediate area being generally smaller than said first plastic film such that said first and second films contact one another around the periphery of said fenestration and the periphery of said first plastic film.
 8. An improved disposable surgical drape as defined in claim 7 wherein said first and second films are essentially continuously bonded together around said fenestration and around the periphery of said first plastic film to thereby form a reservoir for retaining fluid entering therein through said apertures in said second plastic film until said fluid is expelled through said communicating means.
 9. An improved disposable surgical drape as defined in claim 8 wherein said first and second films are heat sealed to form said bond. 